Detergent compositions in tablet form are described, for example, in GB 911204 (Unilever), U.S. Pat. No. 3,953,350 (Kao), JP 60-015500A (Lion), and EP-A-711827 (Unilever) and are sold commercially in Spain. Tablets for machine dishwashing are described in WO96/28530 (P&G). Tablets have several advantages over powdered products: they do not require measuring and are thus easier to handle and dispense into the washload, and they are more compact, hence facilitating more economical storage.
Tablets of a cleaning composition are generally made by compressing or compacting a quantity of the composition in particulate form. It is desirable that tablets have adequate strength when dry, yet disperse and dissolve quickly when added to wash water.
It is known to include materials whose function is to enhance disintegration of tablets when placed in wash water. Some tablets which are sold commercially incorporate urea for this purpose. Urea has a very high solubility in water exceeding 100 gms per 100 ml water at 20.degree. C.